test(forge): add forge parsing spec

Problem: no test coverage for forge link shorthand parsing, URL
parsing, label formatting, or API URL generation.

Solution: add `spec/forge_spec.lua` covering `_parse_shorthand`,
`parse_ref` for all three forges, full URL parsing including nested
GitLab groups, `format_label`, and `_api_url`.

spec/forge_spec.lua

@@ -0,0 +1,354 @@
+require('spec.helpers')
+
+local forge = require('pending.forge')
+
+describe('forge', function()
+  describe('_parse_shorthand', function()
+    it('parses gh: shorthand', function()
+      local ref = forge._parse_shorthand('gh:user/repo#42')
+      assert.is_not_nil(ref)
+      assert.equals('github', ref.forge)
+      assert.equals('user', ref.owner)
+      assert.equals('repo', ref.repo)
+      assert.equals('issue', ref.type)
+      assert.equals(42, ref.number)
+      assert.equals('https://github.com/user/repo/issues/42', ref.url)
+    end)
+
+    it('parses gl: shorthand', function()
+      local ref = forge._parse_shorthand('gl:group/project#15')
+      assert.is_not_nil(ref)
+      assert.equals('gitlab', ref.forge)
+      assert.equals('group', ref.owner)
+      assert.equals('project', ref.repo)
+      assert.equals(15, ref.number)
+    end)
+
+    it('parses cb: shorthand', function()
+      local ref = forge._parse_shorthand('cb:user/repo#3')
+      assert.is_not_nil(ref)
+      assert.equals('codeberg', ref.forge)
+      assert.equals('user', ref.owner)
+      assert.equals('repo', ref.repo)
+      assert.equals(3, ref.number)
+    end)
+
+    it('handles hyphens and dots in owner/repo', function()
+      local ref = forge._parse_shorthand('gh:my-org/my.repo#100')
+      assert.is_not_nil(ref)
+      assert.equals('my-org', ref.owner)
+      assert.equals('my.repo', ref.repo)
+    end)
+
+    it('rejects invalid prefix', function()
+      assert.is_nil(forge._parse_shorthand('xx:user/repo#1'))
+    end)
+
+    it('rejects missing number', function()
+      assert.is_nil(forge._parse_shorthand('gh:user/repo'))
+    end)
+
+    it('rejects missing repo', function()
+      assert.is_nil(forge._parse_shorthand('gh:user#1'))
+    end)
+  end)
+
+  describe('_parse_github_url', function()
+    it('parses issue URL', function()
+      local ref = forge._parse_github_url('https://github.com/user/repo/issues/42')
+      assert.is_not_nil(ref)
+      assert.equals('github', ref.forge)
+      assert.equals('user', ref.owner)
+      assert.equals('repo', ref.repo)
+      assert.equals('issue', ref.type)
+      assert.equals(42, ref.number)
+    end)
+
+    it('parses pull request URL', function()
+      local ref = forge._parse_github_url('https://github.com/user/repo/pull/10')
+      assert.is_not_nil(ref)
+      assert.equals('pull_request', ref.type)
+    end)
+
+    it('rejects non-github URL', function()
+      assert.is_nil(forge._parse_github_url('https://example.com/user/repo/issues/1'))
+    end)
+  end)
+
+  describe('_parse_gitlab_url', function()
+    it('parses issue URL', function()
+      local ref = forge._parse_gitlab_url('https://gitlab.com/group/project/-/issues/15')
+      assert.is_not_nil(ref)
+      assert.equals('gitlab', ref.forge)
+      assert.equals('group', ref.owner)
+      assert.equals('project', ref.repo)
+      assert.equals('issue', ref.type)
+      assert.equals(15, ref.number)
+    end)
+
+    it('parses merge request URL', function()
+      local ref = forge._parse_gitlab_url('https://gitlab.com/group/project/-/merge_requests/5')
+      assert.is_not_nil(ref)
+      assert.equals('merge_request', ref.type)
+    end)
+
+    it('handles nested groups', function()
+      local ref = forge._parse_gitlab_url('https://gitlab.com/org/sub/project/-/issues/1')
+      assert.is_not_nil(ref)
+      assert.equals('org/sub', ref.owner)
+      assert.equals('project', ref.repo)
+    end)
+  end)
+
+  describe('_parse_codeberg_url', function()
+    it('parses issue URL', function()
+      local ref = forge._parse_codeberg_url('https://codeberg.org/user/repo/issues/3')
+      assert.is_not_nil(ref)
+      assert.equals('codeberg', ref.forge)
+      assert.equals('user', ref.owner)
+      assert.equals('repo', ref.repo)
+      assert.equals('issue', ref.type)
+      assert.equals(3, ref.number)
+    end)
+
+    it('parses pull URL', function()
+      local ref = forge._parse_codeberg_url('https://codeberg.org/user/repo/pulls/7')
+      assert.is_not_nil(ref)
+      assert.equals('pull_request', ref.type)
+    end)
+  end)
+
+  describe('parse_ref', function()
+    it('dispatches shorthand', function()
+      local ref = forge.parse_ref('gh:user/repo#1')
+      assert.is_not_nil(ref)
+      assert.equals('github', ref.forge)
+    end)
+
+    it('dispatches GitHub URL', function()
+      local ref = forge.parse_ref('https://github.com/user/repo/issues/1')
+      assert.is_not_nil(ref)
+      assert.equals('github', ref.forge)
+    end)
+
+    it('dispatches GitLab URL', function()
+      local ref = forge.parse_ref('https://gitlab.com/group/project/-/issues/1')
+      assert.is_not_nil(ref)
+      assert.equals('gitlab', ref.forge)
+    end)
+
+    it('returns nil for non-forge token', function()
+      assert.is_nil(forge.parse_ref('hello'))
+      assert.is_nil(forge.parse_ref('due:tomorrow'))
+    end)
+  end)
+
+  describe('_api_url', function()
+    it('builds GitHub API URL', function()
+      local url = forge._api_url({
+        forge = 'github',
+        owner = 'user',
+        repo = 'repo',
+        type = 'issue',
+        number = 42,
+        url = '',
+      })
+      assert.equals('https://api.github.com/repos/user/repo/issues/42', url)
+    end)
+
+    it('builds GitLab API URL for issue', function()
+      local url = forge._api_url({
+        forge = 'gitlab',
+        owner = 'group',
+        repo = 'project',
+        type = 'issue',
+        number = 15,
+        url = '',
+      })
+      assert.equals('https://gitlab.com/api/v4/projects/group%2Fproject/issues/15', url)
+    end)
+
+    it('builds GitLab API URL for merge request', function()
+      local url = forge._api_url({
+        forge = 'gitlab',
+        owner = 'group',
+        repo = 'project',
+        type = 'merge_request',
+        number = 5,
+        url = '',
+      })
+      assert.equals('https://gitlab.com/api/v4/projects/group%2Fproject/merge_requests/5', url)
+    end)
+
+    it('builds Codeberg API URL', function()
+      local url = forge._api_url({
+        forge = 'codeberg',
+        owner = 'user',
+        repo = 'repo',
+        type = 'issue',
+        number = 3,
+        url = '',
+      })
+      assert.equals('https://codeberg.org/api/v1/repos/user/repo/issues/3', url)
+    end)
+  end)
+
+  describe('format_label', function()
+    it('formats with default format', function()
+      local text, hl = forge.format_label({
+        forge = 'github',
+        owner = 'user',
+        repo = 'repo',
+        type = 'issue',
+        number = 42,
+        url = '',
+      }, nil)
+      assert.truthy(text:find('user/repo#42'))
+      assert.equals('PendingForge', hl)
+    end)
+
+    it('uses closed highlight for closed state', function()
+      local _, hl = forge.format_label({
+        forge = 'github',
+        owner = 'user',
+        repo = 'repo',
+        type = 'issue',
+        number = 42,
+        url = '',
+      }, { state = 'closed', fetched_at = '2026-01-01T00:00:00Z' })
+      assert.equals('PendingForgeClosed', hl)
+    end)
+
+    it('uses closed highlight for merged state', function()
+      local _, hl = forge.format_label({
+        forge = 'gitlab',
+        owner = 'group',
+        repo = 'project',
+        type = 'merge_request',
+        number = 5,
+        url = '',
+      }, { state = 'merged', fetched_at = '2026-01-01T00:00:00Z' })
+      assert.equals('PendingForgeClosed', hl)
+    end)
+  end)
+
+  describe('conceal_patterns', function()
+    it('returns base patterns', function()
+      local patterns = forge.conceal_patterns()
+      assert.is_true(#patterns >= 6)
+    end)
+  end)
+end)
+
+describe('forge parse.body integration', function()
+  local parse = require('pending.parse')
+
+  it('extracts gh: shorthand from task text', function()
+    local desc, meta = parse.body('Fix login bug gh:user/repo#42')
+    assert.equals('Fix login bug', desc)
+    assert.is_not_nil(meta.forge_ref)
+    assert.equals('github', meta.forge_ref.forge)
+    assert.equals(42, meta.forge_ref.number)
+  end)
+
+  it('extracts gl: shorthand', function()
+    local desc, meta = parse.body('Update docs gl:group/project#15')
+    assert.equals('Update docs', desc)
+    assert.is_not_nil(meta.forge_ref)
+    assert.equals('gitlab', meta.forge_ref.forge)
+  end)
+
+  it('extracts GitHub URL', function()
+    local desc, meta = parse.body('Fix bug https://github.com/user/repo/issues/10')
+    assert.equals('Fix bug', desc)
+    assert.is_not_nil(meta.forge_ref)
+    assert.equals('github', meta.forge_ref.forge)
+    assert.equals(10, meta.forge_ref.number)
+  end)
+
+  it('combines forge ref with due date', function()
+    local desc, meta = parse.body('Fix bug gh:user/repo#42 due:tomorrow')
+    assert.equals('Fix bug', desc)
+    assert.is_not_nil(meta.forge_ref)
+    assert.is_not_nil(meta.due)
+  end)
+
+  it('combines forge ref with category', function()
+    local desc, meta = parse.body('Fix bug gh:user/repo#42 cat:Work')
+    assert.equals('Fix bug', desc)
+    assert.is_not_nil(meta.forge_ref)
+    assert.equals('Work', meta.cat)
+  end)
+
+  it('leaves non-forge tokens as description', function()
+    local desc, meta = parse.body('Fix the gh: prefix handling')
+    assert.equals('Fix the gh: prefix handling', desc)
+    assert.is_nil(meta.forge_ref)
+  end)
+
+  it('only takes one forge ref', function()
+    local desc, meta = parse.body('Fix gh:a/b#1 gh:c/d#2')
+    assert.equals('Fix gh:a/b#1', desc)
+    assert.is_not_nil(meta.forge_ref)
+    assert.equals('c', meta.forge_ref.owner)
+    assert.equals('d', meta.forge_ref.repo)
+  end)
+end)
+
+describe('forge diff integration', function()
+  local store = require('pending.store')
+  local diff = require('pending.diff')
+
+  it('stores forge_ref in _extra on new task', function()
+    local tmp = os.tmpname()
+    local s = store.new(tmp)
+    s:load()
+    diff.apply({ '- [ ] Fix bug gh:user/repo#42' }, s)
+    local tasks = s:active_tasks()
+    assert.equals(1, #tasks)
+    assert.is_not_nil(tasks[1]._extra)
+    assert.is_not_nil(tasks[1]._extra._forge_ref)
+    assert.equals('github', tasks[1]._extra._forge_ref.forge)
+    assert.equals(42, tasks[1]._extra._forge_ref.number)
+    os.remove(tmp)
+  end)
+
+  it('stores forge_ref in _extra on existing task', function()
+    local tmp = os.tmpname()
+    local s = store.new(tmp)
+    s:load()
+    local task = s:add({ description = 'Fix bug' })
+    s:save()
+    diff.apply({ '/' .. task.id .. '/- [ ] Fix bug gh:user/repo#10' }, s)
+    local updated = s:get(task.id)
+    assert.is_not_nil(updated._extra)
+    assert.is_not_nil(updated._extra._forge_ref)
+    assert.equals(10, updated._extra._forge_ref.number)
+    os.remove(tmp)
+  end)
+
+  it('preserves existing forge_ref when not in parsed line', function()
+    local tmp = os.tmpname()
+    local s = store.new(tmp)
+    s:load()
+    local task = s:add({
+      description = 'Fix bug',
+      _extra = {
+        _forge_ref = {
+          forge = 'github',
+          owner = 'a',
+          repo = 'b',
+          type = 'issue',
+          number = 1,
+          url = '',
+        },
+      },
+    })
+    s:save()
+    diff.apply({ '/' .. task.id .. '/- [ ] Fix bug' }, s)
+    local updated = s:get(task.id)
+    assert.is_not_nil(updated._extra._forge_ref)
+    assert.equals(1, updated._extra._forge_ref.number)
+    os.remove(tmp)
+  end)
+end)